Nakajima S
Keio University, Tokyo, Japan.
Behav Processes. 1992;27(1):65-73. doi: 10.1016/0376-6357(92)90041-B.
Pigeons learned a serial amibiguous discrimination task (FA+, A-, FB-, B+), in which the serial presentation of a feature and one target (FA) and the presentation of the other target alone (B) were followed by an unconditioned stimulus (US), but the serial FB presentation and the presentation of A alone were unreinforced. The successful performance of this task supported Holland's (1983, 1985) model of the feature modulation asserting that the feature occasion-sets each target-US association, rather than Rescorla's (1985) model asserting that the feature modulates the threshold of the US representation. The result that the simultaneous presentation of the feature and the target did not produce better discrimination than the serial presentation suggested a 'bidirectional occasion-setting' function of the feature. However, the insertion of the temporal gap between the feature and the target deteriorated the discrimination, a result that disagreed with previous studies of occasion-setting in the rats. Some possible reasons of the detrimental effect of the gap were discussed, and a unique-cue strategy was suggested as a possible alternative account of the discrimination.
鸽子学习了一个系列性模糊辨别任务（FA+，A-，FB-，B+），其中一个特征与一个目标的系列呈现（FA）以及另一个目标单独呈现（B）之后会跟一个无条件刺激（US），但FB的系列呈现以及单独呈现A则不会得到强化。这个任务的成功完成支持了霍兰德（1983年、1985年）的特征调制模型，该模型认为特征为每个目标-无条件刺激关联设定情境，而不是雷斯克拉（1985年）的模型，后者认为特征调制无条件刺激表征的阈值。特征与目标同时呈现并没有比系列呈现产生更好的辨别效果，这一结果表明了特征的“双向情境设定”功能。然而，在特征与目标之间插入时间间隔会使辨别能力下降，这一结果与之前对大鼠情境设定的研究不一致。文中讨论了间隔产生不利影响的一些可能原因，并提出了一种独特线索策略作为辨别现象的一种可能的替代解释。
